This is a continuation of a discussion from a comment thread elsewhere.
Here is the basic question. When I see an incorrect answer, what would you recommend that I do?
I have always assumed that what I should do is downvote an incorrect answer, and (ideally) post a comment explaining why the answer is incorrect, to help readers understand what the error was. However, apparently in doing so in at least one case, I have managed to hurt one poster's feelings and made him feel like he was under personal attack. That is not my intent, and I don't want to see that happen.
@Ninefingers has suggested that "the best course of action when you disagree with something is to use your vote (you're entitled to do that) - for minor issues (did you mean XYZ?) comments work, but otherwise propose an alternative solution." Can anyone elaborate on what this means? Does this mean: (i) if the answer is incorrect and it is a major error, then downvote, but do not post a comment (and if possible post a correct solution), (ii) if the answer is incorrect and it is a minor error, then downvote and do post a comment? Is that what the community wants me to do? If I see a major error, don't comment on it? And if the person who posted the inaccurate answer asks for an explanation of why they got downvoted, then it's better to just not answer, despite their request?
I'm happy to follow whatever the community norms are. I'm hoping someone can elaborate on what they are.
Unfortunately, cryptography is a technical subject where there are correct and incorrect answers. Incorrect answers can put security at risk -- yet incorrect answers can often be quite hard to spot. It is not uncommon for people to think they have a correct answer, without realizing that their answer is actually incorrect. The policy I have followed is that if I see an inaccuracy that I feel the question-asker (or other readers) needs to know about, I try to actively point out and correct those errors. I've assumed that it is important to post a comment explaining the error, because errors can be hard to spot until they are pointed out (and because the voting process doesn't work if only one person is aware of the subtle error in the post but doesn't tell anyone about it). In addition, if the answerer explicitly asks for comments (as in this case), I try to post them.
However, perhaps what I haven't taken into account is that it is only human to have your feelings hurt if someone tells you that your answer is incorrect. Perhaps @Ninefingers' message is that it is better to let incorrect answers stand, without trying to correct them -- in the interests of keeping the peace, it's better to stick to just downvoting, without trying to call attention to errors in the comments? That creating a welcoming and friendly atmosphere is more important than correcting every technical error? Am I interpreting this feedback correctly?
I'd welcome your thoughts on how the community wants me to handle such situations. Thank you in advance!